As the book describes, some of the strategies pursued by the HFT traders were made possible because of the way the code underlying the system was constructed. As Lessig pointed out way back way in Code and Other Laws of Cyberspace, and revisited in Codev2:

There is regulation of behavior on the Internet and in cyberspace, but that regulation is imposed primarily through code. The differences in the regulations effected through code distinguish different parts of the Internet and cyberspace. In some places, life is fairly free; in other places, it is more controlled. And the difference between these spaces is simply a difference in the architectures of control — that is, a difference in code.

The regulation imposed on the interconnected markets by code was gameable. Indeed, it seems that it could be argued that it was even designed to be gameable…

A phantom layer of “ad laundering” fake websites whose traffic comes largely from bots is used to generate ad-impression revenue. (Compare this with networks of bots on social media networks that connect to each other, send each other messages, and so on, to build up “authentic” profiles of themselves, at least in terms of traffic usage dynamics. Examples: MIT Technlogy Review on Fake Persuaders; or this preprint on The Rise of Social Bots.)

As the world becomes more connected and more and more markets become exercises simply in bit exchange between bots, I suspect we’ll be seeing more and more of these phantom layer/bot audience combinations on the one hand, and high-speed, market stealing, front running algorithms on the other.